Pattern transfer printing elements



' Feb. 25, 1964 R LYNCH ETAL 3,122,093

PATTERN TRANSFER PRINTING ELEMENTS Filed April 12, 1961 fibersRelulively Densely compacted L Fibers Relatively I Loosely CompuctedINVENTORS GREGORY R. LYNCH JOSEPH F. TUSCHER ATTORNEYS United StatesPatent 3 122.093 PATTERFJ TRANSFER PRIN'IHQG ELEMlh TS Gregory R. Lynch,Burlington, and Joseph 1 Tuscher,

Reading, Mass, assignors to The Carters Ink Company, Cambridge, Mass, acorporation of Massachusetts Filed Apr. 12, 1961, Ser. No. 102,555 2Claims. (Cl. lei-149.4)

This invention relates to printing ad more particularly to the printingof patterns, designs, and outlines for decorative or patterningpurposes, or other uses where a deslgn or outline is to be applied on abase surface. The invention consists of a sheet having the desiredpattern printed on one side by means of a readily transferable material,and thus provides a convenient and inexpensive means for marking fabricsor construction materials in dressmaking and home crafts, or forapplying a decoration or other marking to fixed surfaces, such as indecorating windows and walls.

Present techniques for transferring a design or pattern from a print toa work surface include various reproduction and drafting methods, freehand work, the direct attachment of a thin pattern or template, all ofwhich possess disadvantages such as expense, lack of precision, or inrequiring fine skills. Proposals have been made to print a design orpattern on a base sheet which can be laid over the workpiece, and amarking made by applying pressure over the design. According to U.S.Patent No. 482,451, a pattern formed of printers ink mixed with wax andapplied to a paper base may be transferred by pressing a stylus alongthe lines of the design. A similar result may be obtained by tracing adesign with a soft pencil on tracing paper, and then retracing on theopposite side with sufiicient pressure to mark an under-lying surface. Apractical diificulty lies in the pressure applied from a stylus, which,although only a few ounces of total force comes to a unit pressure whichis so very high as to be unsuitable under many conditions. Where theworkpiece is fabric, it tends to shift in following the stylus, and itssoft working surface will yield, causing the paper base to puncture orwrinkle.

Other similar products are described by Maddock, U.S. Patents Nos.2,228,286 and 2,233,791 and Kneale, U.S. Patent No. 2,408,147, theformer employing a cellulose acetate film base, and the latter a waximpregnated paper base. All require a stylus pressure to eifect atransfer and are accordingly not well suited for use on soft surfaces,or under conditions where high unit pressures are to be avoided.

The transfer sheets of this invention utilize a paper base which carriesan outlined pattern of a readily transferred marking material by which apattern, outline, or design may be printed under very light pressures,such as that attained by rubbing the sheet with a teaspoon or the heelof the hand. In the development of such a prodnot, many problems wereencountered which suggested that a sheet of the type sought could not beproduced. Transferable marking materials which adhere well to the basedo not transfer well under light pressures, While those that are softenough to transfer easily generally lack decent adhesive properties.Greater difficulties are encountered where a reusable sheet is to beprovided for the necessary increased thickness of transferable materialtends to result in excessive smudging with soft materials whereas hardermaterials tend to chip from the base. Experiments with various types ofpaper indicate that some of the difiiculties could be avoided byemploying a paper of higher porosity. That however resulted in a base ofgreatly reduced transparency which could not be sacrificed because ofthe need of seeing the underlying surface for proper patternpositioning. Although high transparency and high porosity arecontradictory properties, a combination of a paper base composition andreadily transferable material was found which would yield the desiredproduct. The transfer material is a relatively soft yet coherent waxycomposition containing coloring or pigment, of a type commonly employedin carbon paper. Not all carbon paper dopes, however, are suitable, assome are too soft and smudge easily while others are too hard and do nottransfer under the low pressures required for this product.

Adherence and transfer properties were atained by the discovery of acomposite paper structure which combined strength, weight, transparency,and porosity in a single sheet. A paper was formulated for use in thesheet of this invention, having a porous fibrous side to which thetransfer material would adhere, while being more highly compacted andtranslucent at the opposite side and inwardly through a sufiicientfraction of the thickness that over-all translucency is provided.

The wax transfer material may therefore be applied so as to penetratesubstantially into the body or" the sheet and also to extendsubstantially from the surface of the sheet, being in the nature of ablock printing character securely anchored physically within the fibersat the printed surface. The waxy transfer material is thus firmlysecured physically to the sheet without requiring hiherent adhesiveproperties, and may be formulated to possess those properties givinggood transfer under conditions of use.

The backing sheet of this invention may accordingly be characterized asa paper base having its fibers relatively loosely compacted at onesurface to provide for penetration of the transfer material (applied inthe liquid state) but being over-all more densely compacted andtranslucent. The degree of compactness may roughly be set forth on thebasis of paraffin penetration values, and air resistance values Whilethe over-all transparency can be related to density and weight.

Suitable papers have been found to have the following characteristics:

Ream weight, 20-35 lbs. (500 sheets 24" x 36") TAPPl T-Z-lG-M- LSPorosity (air resistance),

Paraflin absorption, over 15, TAPPI T467M48 The relative compactness ofthe opposite surfaces may be provided by machine glazing the paper,whereby one surface is calendered or pressed to a more dense conditionwhile the fibers of the opposite surface (the felt side) remain looseand more distantly spaced. Alternatively, yo separate paper furnishesmay be employed, first one of stock yielding a transparent sheet, e.g.well beaten relatively long fibers, followed by an over-coating from asecondary head box of less well beaten fibers yielding a more porousbase. Numerous other ways may also occur to those sln'lled in the papermaking art, by Way of proper selection of paper stock, fiber length andtype, degree of beating, degree of cutting, provision of fillers,binders, etc., all of which have definite effects which may be utilizedselectively to produce the desired result. It is accordinglycontemplated that a paper maker, given specifications as to the type ofpaper required, may readily produce it without so much experimentationas to amount to invention. The present disclosure confirms that anessentially translucent, relatively heavy weight paper may be maderaving one surface loosely compacted and of relatively high porosity(these intrinsically lacking in transparency) without destroying 20-35seconds, TAPPI *Standard test procedures of the Technical Association ofthe Pulp and Paper Industry.

5 wh le mixing and grinding thoroughly. The dope is applied as a hotmelt at about 180 1 or higher.

The manufacture of the printing elements features the application of arelatively large amount of dope to the base sheet under conditions whichassure adequate bonding. This is accomplished by an intaglio printingprocess employing an engraved print roll 24 in which the desired patternis deeply etched to provide for an application of dope of at least onemil. Typically the engraving will be based on a half-tone screen of 40cells per inch separated by a wall thickness of 50a, 100-150,1 in depth.

The roll is heated to apply the dope in its molten condition and thepaper is heated to maintain the dope melted during and afterapplication. As illustrated schematically in FIG. 4, the paper basesheet 13 is passed from a feed roll 29, over a hot plate 22, and thenbetween the print roll 24 and an impression cylinder 26. The print roll24 revolves with its lower portion in a trough 28 of molten dope, theexcess of which is removed by means of a doctor blade 39. A pattern ofdope corresponding to the engraving on the print roll is thereby appliedto the paper 19. The paper 19 next feeds over a second hot plate 32,which keeps the dope molten sufficiently long for proper penetration,then passes over a chill plate 34 to harden the dope, and is finallywound on a take-up roll 36.

Typically the print roll 24 and hot plates 22 and 32 are heated by steamat 5 pounds p.s.i.g. and the chill plate is cooled by water at about 52F.

A pattern transfer printing element 4% bearing a dolls dress pattern isshown in FIG. 2, and in FIG. 3 is shown its manner of use, wherein theelement 40 is laid over a fabric 41 and transfer is efiected by rubbingthe back (top) of the element li htly with a spoon 42. As many as 30prints can be made in this manner.

A printing element formed in the manner described above will have apattern of dope of a total thickness of about 1 to 2 mils, of whichabout half (0.5-1 mils) is penetrated into the backing sheet and theremainder projects from the surface. This application is significantlyheavier than encountered in the manufacture of ordinary carbon papers,and the product as a whole also differs from ordinary carbon papers inthat the dope backing sheet is much heavier, while still beingtranslucent, and of suitably high porosity at the doped surface.

Although this invention has been described with reference to onepreferred embodiment, numerous modifications respecting the exact typesof paper and dope to be used will occur to those skilled in the art andfamiliar with this disclosure, and such may be made without departingfrom the scope of this invention. In particular, dopes will beformulated with varying degrees of hardness or softness within thecriteria herein set forth, for specific uses. Where patterns are to betransrerred to a hard surface, such as glass, a softer dope is betterthan a harder one.

Variations in the paper backing sheet may also be made as long as therequisite properties of translucency, stiffness, and porosity aremaintained.

Having thus disclosed my invention and described in detail a preferredembodiment thereof, I claim and deire to secure by Letters Patent:

1. A printing element in the form of a paper sheet base carrying on oneside an outlined pattern of waxy marking material transferable to anunderlying surface under a pressure of grams applied by a sphere onehalfinch in diameter to the opposite side of said sheet, said sheet being atranslucent paper of 20-35 pounds per ream of 500 sheets 24" X36",having a porosity of 20 30 seconds and a paraffin absorption in excessof 15, said marking material being a waxy carbon dope having apenetrometer value greater than 0.25 mm, and applied to a thickness of1.0-2.0 mils with at least 0.5 mils penetra ing into the surface of saidsheet.

2. A printing element in the form of a paper sheet base carrying on oneside an outlined pattern of waxy marking material transferable to anunderlying surface under a pressure of 100 grams applied by a sphereonehalf inch in diameter to the opposite side of said sheet, said papersheet being translucent and having fibers relatively loosely compactedon said one side, and relatively densely compacted on said oppositeside, with part of said transferable material penetrating partially intothe sheet and embedding fibers at said one side without being present atsaid other side, part of said transferable material also lying outwardlyfrom said one side to form a print contact portion raised at least 0.5mil from the surface of said sheet.

References Cited in the file of this patent UNITED STATES PATENTS482,451 Koskul Sept. 13, 1892 1,063,791 Hanington et a1. June 3, 19131,911,592 Supligeau et al. May 30, 1943 2,322,445 Huber June 22, 19432,382,920 Schaeffer Aug. 14, 1945 2,582,932 Lustbader Jan. 15, 1952

1. A PRINTING ELEMENT IN THE FORM OF A PAPER SHEET BASE CARRYING ON ONESIDE AN OUTLINED PATTERN OF WAXY MARKING MATERIAL TRANSFERABLE TO ANUNDERLYING SURFACE UNDER A PRESSURE OF 100 GRAMS APPLIED BY A SPHEREONEHALF INCH IN DIAMETER TO THE OPPOSITE SIDE OF SAID SHEET, SAID SHEETBEING A TRANSLUCENT PAPER OF 20-35 POUNDS PER REAM OF 500 SHEETS 24" X36", HAVING A POROSITY OF 2030 SECONDS AND A PARAFFIN ABSORPTION INEXCESS OF 15, SAID MARKING MATERIAL BEING A WAXY CARBON DOPE HAVING APENETROMETER VALUE GREATER THAN 0.25 MM., AND APPLIED TO A THICKNESS OF1.0-2.0 MILS WITH AT LEAST 0.5 MILS PENETRATING INTO THE SURFACE OF SAIDSHEET.